Nutritional modulation of CK2 in Saccharomyces cerevisiae: regulating the activity of a constitutive enzyme

  • Farida Tripodi
  • Claudia Cirulli
  • Veronica Reghellin
  • Luca Brambilla
  • Oriano Marin
  • Paola Coccetti
Article

DOI: 10.1007/s11010-011-0958-3

Cite this article as:
Tripodi, F., Cirulli, C., Reghellin, V. et al. Mol Cell Biochem (2011) 356: 269. doi:10.1007/s11010-011-0958-3

Abstract

CK2 is a highly conserved protein kinase involved in different cellular processes, which shows a higher activity in actively proliferating mammalian cells and in various types of cancer and cancer cell lines. We recently demonstrated that CK2 activity is strongly influenced by growth rate in yeast cells as well. Here, we extend our previous findings and show that, in cells grown in either glucose or ethanol-supplemented media, CK2 presents no alteration in Km for both the ATP and the peptide substrate RRRADDSDDDDD, while a significant increase in Vmax is observed. In chemostat-grown cells, no difference of CK2 activity was observed in cells grown at the same dilution rate in media supplemented with either ethanol or glucose, excluding the contribution of carbon metabolism on CK2 activity. By using the eIF2β-derived peptide, which can be phosphorylated by the holoenzyme but not by the free catalytic subunits, we show that the holoenzyme activity requires the concurrent presence of both β and β′ encoding genes. Finally, conditions of nitrogen deprivation leading to a G0-like arrest result in a decrease of total CK2 activity, but have no effect on the activity of the holoenzyme. These findings newly indicate a regulatory role of β and β′ subunits of CK2 in the nutrient response.

Keywords

Saccharomyces cerevisiae Growth rate Nitrogen starvation Protein kinase CK2 CK2 Activity CK2 Holoenzyme 

Copyright information

© Springer Science+Business Media, LLC. 2011

Authors and Affiliations

  • Farida Tripodi
    • 1
  • Claudia Cirulli
    • 1
  • Veronica Reghellin
    • 1
    • 3
  • Luca Brambilla
    • 1
  • Oriano Marin
    • 2
  • Paola Coccetti
    • 1
  1. 1.Dipartimento di Biotecnologie e BioscienzeUniversità di Milano-BicoccaMilanItaly
  2. 2.Dipartimento di Chimica BiologicaUniversità di PadovaPaduaItaly
  3. 3.INGM Istituto Nazionale Genetica MolecolareMilanItaly

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